Various types of storage cases for magnetic cassette tapes (herein after referred to as storage case) are proposed according to the configuration of the magnetic cassette to be stored. Referring now to FIG. 46 and FIG. 47, a storage case for digital video cassettes (hereinafter referred to as “DVCs”) and a magnetic tape cassette for the DVCs of the related art will be described by way of example.
The storage case 1441 shown in FIG. 46 comprises a storage section 1443 for storing the magnetic tape cassette 1481 shown in FIG. 47, a lid section 1445, and a connecting section 1447. The storage section 1443 comprises a first plate portion 1451, and a first sidewall portion 1453 formed integrally along the outer periphery of the first plate portion 1451, and a pair of reel locking ribs 1445a, 1445b formed on the first plate portion 1451 at the positions somewhat closer to the rear side than to the front side. When the magnetic tape cassette 1481 shown in FIG. 47 is stored, it will be fitted within the first sidewall portion 1453 in the state shown by a phantom line in FIG. 46 when it is properly stored.
The lid section 1445 comprises a second plate portion 1461, and a second sidewall portion 1463 formed integrally along three sides of the outer periphery of the second plate portion 1461. The connecting section 1447 comprises a third plate portion 1471 and thin portions 1473a, 1473b formed on both sides thereof. These thin portions 1473a, 1473b enable the storage section 1443 and the lid section 1445 to close as a book.
Outside of the first sidewall portion 1453 that defines the storage section 1443, there is provided an overhanging portion 1451a that is formed by a part of the first plate portion 1451 in an overhanging manner. Therefore, even when the storage section 1443 and the lid section 1445 are closed and the second sidewall portion 1463 of the lid section 1445 is fitted around the first sidewall portion 1453 of the storage section 1443, the overhanging portion 1451a prevents the storage section 1443 from getting into the lid section 1445, and thus the thickness of the case may be maintained as a whole.
There are formed a recess 1453a, or a locked portion, on the outer surface of the fist sidewall portion 1453, and a projection 1463a, or a locking portion, on the inner surface of the second sidewall portion 1463 at the position corresponding to the recess portion 1453a when the storage section 1443 and the lid section 1445 are closed. Therefore, when the storage section 1443 and the lid section 1445 are closed with respect to each other, the projection 1463a and the recess 1453a engage so as to prevent an accidental opening of the storage section 1443 and the lid section 1445.
Referring now to FIG. 47, the magnetic tape cassette 1481 will be described. FIG. 47 is a perspective view of the magnetic tape cassette 1481 when viewed from the bottom side, in which an upper cassette half 1483 is situated below the lower cassette half 1485. There are formed circular openings 1487a, 1487b at two locations on the lower cassette half 1485, and engaging portions 1489a, 1489b integrally formed with the reel hubs (not shown) on which the magnetic tape is wound are exposed therefrom.
The engaging portions 1489a, 1489b have a function to unwinding and winding the magnetic tape when it is mounted in the VTR, and a function to engage the ribs 1455a, 1455b for engaging the reel and prevents rattling of the magnetic tape cassette 1481 when it is stored in the storage case 1441.
On the front side of the magnetic tape cassette 1481, an outer lid 1491 is provided for pivotal movement, and when it is mounted in the VTR or the like, the magnetic tape is pulled out after the outer lid 1491 is pivoted as shown by the arrow A in FIG. 47. There is formed a recessed opening 1493 inside the outer lid 1491 at near the center in such a manner that the upper and lower cassette halves 1483, 1485 are notched, and there is provided a shoulder 1495 on one end of the opening 1493 on the side of the lower cassette half 1485.
The magnetic tape cassette 1481 may be stored in the storage case 1441 by fitting the magnetic tape cassette 1481 in the sidewall portion 1453 as shown by a phantom line in FIG. 46, and pushing and inserting the ribs 1455b, 1455a for engaging the reels into circular engaging holes B formed at the center of the engaging portion 1489a, 1489b, whereby the positional restriction of the magnetic tape cassette 1481 is made and stored appropriately.
However, in the structure of the storage case 1441 described above, the following problem was recognized when the magnetic tape cassette 1481 is stored. When the storage section 1443 and the lid section 1445 are closed as described above, the second sidewall portion 1463 of the lid section 1445 is fitted on the outside of the first sidewall portion 1453 of the storage section 1443 under the normal situation. However, when the both side surface of the second sidewall portion 1463 of the lid section 1445 are pressed, the second sidewall portion 1463 deflects by the pressing force, and thus the sidewall portion 1453 of the storage section 1443 and the sidewall portion 1463 of the lid section 1445 abut against each other when the storage section 1443 and the lid section 1445 are closed, thereby causing imperfect closing. Especially, in order to improve sealing performance of the storage case 1441, the clearance between the first sidewall portion 1453 of the storage section 1443 and the second sidewall portion 1463 of the lid section 1445 have to be reduced as small as possible. However, when the clearance is reduced, a slight pressurizing movement causes abutment between the sidewall portions 1453 and 1463, thereby causing imperfect closing.
In addition, depending on the extent of the pressing force, there may be a case where the second sidewall portion 1463 of the lid section 1445 comes inside the first sidewall portion 1453 of the storage section 1443, which also causes imperfect closing. When it is stored in the badly closed state for a long time, the storage case is subjected to plastic deformation, which is not preferable.
With such a circumstance in view, it is the first object of the present invention to provide a magnetic tape cassette storage case in which imperfect closing can be prevented.
Various storage cases for magnetic tape cassettes are proposed depending on the configuration of the magnetic tape cassette to be stored. Referring to FIG. 48 and FIG. 49, the storage case and the magnetic tape cassette of the related art will be described by way of example.
The storage case 1571 shown in FIG. 48 and FIG. 49 is formed integrally of synthetic resin. The storage case 1571 comprises a storage section 1573 for storing a magnetic tape cassette T, a lid section 1575, and a connecting section 1577 for connecting the storage section 1573 and the lid section 1575 so as to enable the opening-closing motion. The storage section 1573 comprises a first plate portion 1581, and a first sidewall portion 1583 formed integrally along the outer periphery thereof, and the lid section 1575 comprises a second plate portion 1585 and a second sidewall portion 1587 formed integrally along the outer periphery thereof. When the magnetic tape cassette T is appropriately stored in the storage case 1571, the magnetic tape cassette T is fitted in the first sidewall portion 1583 in the state shown by a phantom line in FIG. 49.
On the outsides of the plate portions 1581, 1585, and of the connecting section 1577, there is formed an information sheet holding portion 1601. The information sheet holding portion 1601 is used for storing information sheets 1603 such as a label or a memo on which data or the like relating the magnetic tape cassette T is listed. The information sheet holding portion 1601 is constructed in such a manner that recessed portions 1605 are formed in part on the respective outsides of the plate portions 1581, 1585 and of the connecting section 1577, and almost the whole part of the recessed portions 1605 are covered by a transparent sheet 1607 of flexible synthetic resin.
The sheet 1607 is welded on the plate portions 1581, 1585 at both ends 1607a, 1607b of the recessed portion 1605. Therefore, the information sheet 1603 may be inserted from the opened end of the sheet 1607 and held in the information sheet holding portion 1601, in other words, between the sheet 1607 and the outsides of the plate portions 1581, 1585, and the connecting section 1577.
When the magnetic tape cassette T is stored in the storage case 1571, the information sheet 1603 with data such as the recorded contents or the like is listed thereon is inserted into the information sheet holding portion 1601. In this case, when the information sheet 1603 is small in size, it can be accommodated within the information sheet holding portion 1601. However, when there are many recorded contents to be listed, the information sheet 1603 must be large in size as a matter of course, and thus it cannot be accommodated in the information sheet holding portion 1601 as shown in the figure.
The portion of the information sheet 1603 that cannot be accommodated is bent and deformed outward along the shoulder between the recessed portion 1605 and the plate portions 1581, 1585. The portion of the information sheet 1603 that cannot be accommodated may be damaged or get soiled when the storage case 1571 is carried around. In addition, the same problem may arise when the storage cased 1571 stacked in layers are transported and when it is stored in the rack.
In contrast to it, when the information sheet 1603 is small, the problem of damage or dirt does not arise, but the information sheet 1603 may get hung up at the shoulder between the recessed portion 1605 and the plate portions 1581, 1585 when it is taken out from the information sheet holding portion 1601, and thus there is the problem in that it is difficult to take the information sheet 1603.
In addition, since the transparent sheet 1607 covers almost the entire surface of the recessed portion 1605, the information sheets 1603 when the number of the information sheets increases, it will further be difficult to take the information sheet 1603 out. Therefore, the number of the information sheets 1605 to be held must be reduced, and thus the number of the information sheets that can be held is small.
With such a circumstance in view, it is the second object of the present invention to provide a magnetic tape cassette storage case in which the information sheets relating to the magnetic tape cassette can be kept without giving damage or dirt, in which the information sheets can easily be taken out, and in which many information sheets can be held.
Various types of storage cases for magnetic tape cassettes are proposed according to the configuration of the magnetic tape cassette to be stored. Referring now to FIG. 50 to FIG. 53, the storage case and the magnetic tape cassette for DVCs of the related art will be described by way of example.
The storage case 1850 shown in FIG. 50 comprises a storage section 1701 for storing the magnetic tape cassette 1881 shown in FIG. 51, a lid section 1702 for opening and closing with respect to the storage section 1701 as a book, and a connecting section 1703 for connecting the storage section 1701 and the lid section 1702. The storage section 1701 comprises a first plate portion 1704, a first sidewall portion 1705 formed integrally along the outer periphery of the first plate portion 1704 in the shape of a frame, reel locking ribs 1706a, 1706b formed on the first plate portion 1704 at the positions somewhat closer to the rear side than to the front side, and an opening locking rib 1707 formed on the first plate portion 1704 at the position somewhat closer to the front side in a V-shape in plan view.
The magnetic tape cassette 1881 shown in FIG. 51 is stored in the storage section 1701. When it is properly stored, it is loosely fitted in the first sidewall portion 1705 as shown in a phantom line in FIG. 50.
The lid section 1702 comprises a second plate portion 1708, and a second sidewall portion 1709 formed integrally along three sides of the outer periphery of the second plate portion 1708. The connecting section 1703 comprises the third plate portion 1810. The third plate portion 1810 comprises thin portions 1810a, 1810b on both sides thereof. These thin portions 1810a, 1810b the storage section 1701 and the lid section 1702 to open and close as a book. When the storage case 1850 is closed, the first sidewall portion 1705 and the second sidewall portion 1709 are fitted in parallel with each other in such a manner that the second sidewall portion 1709 is fitted around the outside of the first sidewall portion 1705.
Outside of the first sidewall portion 1705 that defines the storage section 1701, there is provided a first overhanging portion 1704a that is formed by a part of the first plate portion 1704 in an overhanging manner. Therefore, even when the storage section 1701 and the lid section 1702 are closed, and the second sidewall portion 1709 of the lid section 1702 is fitted around the first sidewall portion 1705 of the storage section 1701, the first overhanging portion 1704a prevents the storage section 1701 from getting into the lid section 1702, and thus the thickness of the storage case may be maintained as a whole.
There are formed locking recesses 1705a in a trough shape on the outer wall surface on both sides of the first sidewall portion 1705 and a locking recess 1705b in a trough shape almost at the center of the outer wall surface on the rear side, and locking projections 1709a at the positions on the inner wall surface of the second sidewall portion 1709 corresponding to the locking recesses 1705a and a locking projection 1709b at the position corresponding to the locking recess 1705b. 
Therefore, when the storage section 1701 and the lid section 1702 are closed, the locking projection 1709a engages the locking recess 1705a, and the locking projection 1709b engages the locking recess 1706b so as to prevent an accidental opening of the storage section 1701 and the lid section 1702.
The first sidewall portion 1705 is formed with engaging recesses 1811a, 1811b on the first sidewall portion 1705, and the second sidewall portion 1709 is formed with engaging recesses 1811a, 1811b and the same number of positioning ribs 1862a, 1862b on the inner wall surface thereof. When the storage case 1850 is closed, the engaging recesses 1811a, 1811b engage the positioning ribs 1862a, 1862b respectively. This engagement revents the first sidewall portion 1705 and the second sidewall portion 1709 from moving in parallel with each other.
When the storage case 1850 is closed, the positioning ribs 1862a, 1862b are inserted into the engaging recesses 1811a, 1811b respectively for positioning of the members. Therefore, engagement between the locking projections 1709a, 1709b and the locking recesses 1705a, 1706b is ensured, and thus the lid section 1702 can be positioned at the appropriate position.
A plurality of cassette holding members 1813 are formed on the side of the storage section between the inner surface of the first plate portion 1704 and the inner wall surface of the first sidewall section 1705. In the same manner, a plurality of cassette holding members 1814 are formed on the side of the lid section between the inner surface of the second plate portion 1708 and the inner wall surface of the second sidewall portion 1709. When the magnetic tape cassette 1881 is stored in the storage case 1850 by these cassette storage holding members 1813, 1814, and the storage case 1850 is closed, the magnetic tape cassette 1881 will never come into direct contact with the first plate portion 1704 and the second plate portion 1708, and the first sidewall portion 1705 and the second sidewall portion 1709 under normal conditions.
Referring now to FIG. 51, the magnetic tape cassette 1881 will be described. FIG. 51 is a perspective view of the magnetic tape cassette 1881 viewed from the bottom side, and thus the upper cassette half 1883 is shown below the lower cassette half 1885.
There are formed circular openings 1887a, 1887b at two locations on the lower cassette half 1885, and engaging portions 1889a, 1889b integrally formed with the reel hubs (not shown) on which the magnetic tape is wound are exposed therefrom. The engaging portions 1889a, 1889b have a function to unwinding and winding the magnetic tape when it is mounted in the video tape recorder (VTR).
On the front side of the magnetic tape cassette 1881, an outer lid 1891 is provided for pivotal movement, and when it is mounted in the VTR or the like, the magnetic tape is pulled out after the outer lid 1891 is pivoted as shown by the arrow A in FIG. 51. There is formed a recessed front opening 1893 inside the outer lid 1891 at near the center in such a manner that the upper and lower cassette halves 1883, 1885 are notched, and there is provided a shoulder 1895 on one end of the front opening 1893. Both of them perform specific functions when the magnetic tape cassette 1881 is mounted in the VTR.
In order to mount the magnetic tape set 1881 in the storage case 1850, the magnetic tape cassette 1881 is inserted in the first sidewall portion 1705 with the front opening 1893 faced downward, which is the position turned upside down from the position shown in FIG. 51, and with the front opening 1893 faced toward the opening locking rib 1707. Consequently, the magnetic tape cassette 1881 is stored in the storage section 1701 as shown by phantom line in FIG. 50. Then, by overlaying the lid section 1702 on the storage section 1701 by the use of the connecting section 1703 as to close a book, the locking projections 1709a, 1709b engage the locking recesses 1705a, 1706b to close the storage section 1701 and the lid section 1702, and thus the magnetic tape cassette 1881 is protected and prevented dust from entering therein.
The construction of the storage case 1850 and the magnetic tape cassette 1881 and the closing action thereof has been described so far. On the other hand, when the magnetic tape cassette 1881 is used, it is necessary to take the magnetic cassette 1881 from the storage case 1850 by releasing engagement between the locking projections 1709a, 1709b and the locking recesses 1705a, 1706b. In order to take out the magnetic cassette, the storage section 1701 and the lid section 1702 are pulled in the opposite directions with fingers placed on one end of the storage case 1850 as shown by phantom lines in FIG. 52 and FIG. 53. However, the storage case 1850 of the related art has a following problem.
In a state where the storage section 1701 and the lid section 1702 are closed, as shown in FIG. 52, a first overhanging portion 1704a projects from the end of the storage section 1701, and a second overhanging portion 1708a projects from the end of the lid section 1702. The person who tries to open the storage case 1850, or the user, places his/her thumbs in about the center of the storage case 1850, or in the vicinity of the position where the locking projection 1709b and the locking recess 1706b are engaged, and pulls them in the opposite directions with his/her thumbs hooked on the first and second overhanging portions 1704a, 1708a as shown in FIG. 52 and FIG. 53 by phantom lines.
When such a pulling operation is performed, the locking projection 1709b gets out of the locking recess 1706b, and at almost the same time with it, the locking projection 1709a gets out of the locking recess 1705a and the storage case 1850 is opened. However, a force is required to release engagement between the locking projection 1709b and the locking recess 1706b, and when a force is exerted by thumbs, apart of the second sidewall portion 1709 are pressed in the direction shown by an arrow a in FIG. 52. As a consequent, there is a problem in that the locking projection 1709b is pressed toward the locking recess 1706b and thus the storage case 1850 resists being opened on the contrary.
In order to solve this problem, a measure to eliminate the locking projection 1709b and the locking recess 1706b is conceivable. However, in such a construction, engagement between the storage section 1701 and the lid section 1702 becomes loose, which may result in another problems such as accidental opening of, and increase in possibility of entering of dust or the like into, the storage case 1850. Since dust attached on the magnetic tape may cause a drop out of signals during recording and playing, it is necessary to lock the storage section 1701 and the lid section 1702 tightly.
With such a problem in view, the third object of the present invention is to provide a magnetic tape cassette storage case which is superior in hermeticity between the storage section and the lid section, and which is easy to open and close.
Various types of storage cases for magnetic tape cassettes are proposed depending on the configuration of the magnetic tape cassette to be stored. Referring now to FIG. 54 to FIG. 57, a storage case and a magnetic tape cassette for DVCs of the related art will be described by way of example.
The storage case 2150 shown in FIG. 54 comprises a storage section 1901 for storing the magnetic tape cassette 2081 shown in FIG. 55, a lid section 1902 for covering the storage section 1901, and a connecting section 1903 for connecting the storage section 1901 and the lid section 1902. The storage section 1901 comprises a first plate portion 1904, a first sidewall portion 1905 formed integrally along the outer periphery of the first plate portion 1904, reel engaging ribs 1906a, 1906b formed on the first plate portion 1904 at the positions somewhat closer to the rear side than to the front side, and a rib 1907 formed on the first plate 1904 at the position somewhat closer to the front side in a V-shape in cross section. When the magnetic tape cassette 2081 shown in FIG. 55 is properly stored, it is loosely fitted in the first sidewall portion 1905 as shown by a phantom line in FIG. 54.
The lid section 1902 comprises a second plate portion 1908 and a second sidewall portion 1909 formed integrally along three sides of the outer periphery of the second plate portion 1908. The connecting section 1903 comprises thin portions 2010a, 2010b formed on both sides of the third plate portion 2010, which enables the storage section 1901 and the lid section 1902 to close as a book. When the storage case 2150 is closed, the second sidewall portion 1905 and the second sidewall portion 1909 are fitted in parallel with each other.
Outside of the first sidewall portion 1905 that defines the storage section 1901, there is provided an overhanging portion 1904a that is formed by a part of the first plate portion 1904 in an overhanging manner. Therefore, even when the storage section 1901 and the lid section 1902 are closed, and the second sidewall portion 1909 of the lid section 1902 is fitted around the first sidewall portion 1905 of the storage section 1901, the overhanging portion 1904a prevents the storage section 1901 from getting into the lid section 1902, and thus the thickness of the storage case may be maintained as a whole. The outer surface of the first sidewall portion 1905 is formed with a recessed locking portion 1905a and the inner side surface of the second sidewall portion 1909 is formed with a locking projection 1909a at the position corresponding to the locking portion 1905a when the storage section 1901 and the lid section 1902 are closed. Therefore, when the storage section 1901 and the lid section 1902 are closed, the locking projection 1909a engages the locking portion 1905a to prevent an accidental opening of the storage section 1901 and the lid section 1902.
The first sidewall portion 1905 is formed with engaging recess 2011a, 2011b, and the inner surface of the second sidewall portion 1909 is provided with the same number of positioning ribs 2062a, 2062b as the engaging recesses. When the case is closed, the engaging recess 2011a engages with the positioning rib 2062a. In the same manner, the engaging recess 2011b engages with the positioning rib 2062b. Such engagement prevents the first sidewall portion 1905 and the second sidewall portion 1909 from moving in parallel with each other. When the case is closed, the positioning ribs 2062a, 2062b are inserted into the engaging recesses 2011a, 2011b for positioning between members. Therefore, engagement between the locking projections 1909a, 1909b and the locking portions 1905a, 1905b is ensured, and thus the lid section 1902 can be positioned at the appropriate position.
A plurality of cassette holding members 2013 are formed on the side of the storage section between the inner surface of the first plate portion 1904 and the inner surface of the first sidewall portion 1905. In the same manner, a plurality of cassette holding member 2014 are formed on the side of the lid section between the inner surface of the second plate portion 1908 and the inner surface of the second sidewall portion 1909. When the magnetic tape cassette is stored in the storage case 2050 by these cassette holding members 2013 and 2014, and the storage case 2050 is closed, the magnetic tape cassette will never come into direct contact with the first plate portion 1904 and the second plate portion 1908, and the first sidewall portion 1905 and the second sidewall portion 1909 under normal conditions.
Referring now to FIG. 55, the magnetic tape cassette 2081 is described. FIG. 55 is a perspective view of the magnetic tape cassette 2081 viewed from the bottom side, and thus the upper cassette half 2083 is shown below the lower cassette half 2085. There are formed circular openings 2087a, 2087b at two locations on the lower cassette half 2085, and engaging portions 2089a, 2089b integrally formed with the reel hubs (not shown) on which the magnetic tape is wound are exposed therefrom. The engaging portions 2089a, 2089b have a function to unwinding and winding the magnetic tape when it is mounted in the video tape recorder (VTR).
On the front side of the magnetic tape cassette 2081, an outer lid 2091 is provided for pivotal movement, and when it is mounted in the VTR or the like, the magnetic tape is pulled out after the outer lid 2091 is pivoted as shown by the arrow A in FIG. 55. There is formed a recessed front opening 2093 inside the outer lid 2091 at near the center in such a manner that the upper and lower cassette halves 2083, 2085 are notched, and there is provided a shoulder 2095 on one end of the front opening 2093.
In order to mount the magnetic tape cassette 2081 in the storage case 2150, the magnetic tape cassette 2081 is inserted in the first sidewall portion 1905 with the front opening 2093 faced downward, which is the position turned upside down from the position shown in FIG. 55, and with the front opening 2093 faced toward the rib 1907.
In such a storage case described above, when a instantaneous or continuous pressing force acts upon the second plate portion 1908 of the lid section 1902 in the vertical direction in the state that the storage case is closed, the following phenomenon is observed.
In a first place, a resilient deformation occurs on the second plate portion 1908. The resilient deformation is, for example, a deformation shown by dashed lines in FIG. 56. As is apparent from FIG. 56, such deformation hinders parallel fitting between the second sidewall portion 1909 on the lid section 1902 and the first sidewall section 1905 on the storage section 1901, thereby hindering engagement between the positioning ribs 2062a, 2062b and the engaging recesses 2011a, 2011b respectively. In other words, as a result of the resilient deformation, as shown in FIG. 57, the second sidewall portion 1909 and the positioning ribs 2062a, 2062b are shifted outwardly with respect to the storage case 2150 (in the direction shown by the arrow Dr in FIG. 57) and deformed, so that imperfect engagement between the positioning ribs 2062a, 2062b and the engaging recesses 2011a, 2011b occurs. In addition, as a result of the pressing force and the imperfect engagement described above, a phenomenon that the lid section 1902 abnormally gets into the storage section 1901 occurs. The resilient deformation is obvious in the direction longitudinally of the storage case. When it is further pressed, deformation along the shorter dimension as well, thereby the entire storage case 2150 suffers from deformation.
In addition, when the deformed state of the storage case 2150 continues for a long time, each member is plastically deformed, and thus restoration to the normal state may become impossible. In other words, the entire storage case 2150 may be deformed permanently, and thus it may cause troubles in hermeticity, engaging performance, cassette storing capability of the storage case 2150 that used to be satisfactory.
With such a circumstance in view, it is the fourth object of the present invention to provide a storage case in which a shift or deformation of the sidewall portion resulting from resilient deformation of the members may be prevented.
Various types of storage cases for magnetic tape cassettes are proposed depending on the configuration of the magnetic tape cassette to be stored. Referring now to FIG. 58 and FIG. 59, the storage case and the DVC used in the broadcasting station of the related art will be described by way of example.
The storage case 2350 shown in FIG. 58 comprises a storage section 2201 for storing the magnetic tape cassette 2381 shown in FIG. 59, the lid section 2202 for covering the storage section 2201, and a connecting section 2203 for connecting the storage section 2201 and the lid section 2202 for pivotal movement. The storage section 2201 comprises a first plate portion 2204, a first sidewall portion 2205 formed integrally along the outer periphery of the first plate portion 2204, reel locking ribs 2206a, 2206b formed on the first plate portion 2204 at the positions somewhat closer to the rear side than to the front side, and a opening locking rib 2207 formed on the first plate 2204 at the position a bit close to the front side in a V-shape in cross section. When the magnetic tape cassette 2381 shown in FIG. 59 is properly stored, it is fitted in the first sidewall portion 2205 as shown by a phantom lien in FIG. 58.
The lid section 2202 comprises a second plate portion 2208 and a second sidewall portion 2209 formed integrally along three sides of the outer periphery of the second plate portion 2208. The connecting section 2203 comprises thin portions 2310a, 2310b formed on both sides of the third plate portion 2010, which enables the storage section 2201 and the lid section 2202 to close as a book. When the storage case 2350 is closed, the first sidewall portion 2205 and the second sidewall portion 2209 are fitted in parallel with each other.
Outside of the first sidewall portion 2205 that defines the storage section 2201, there is provided an overhanging portion 2204a that is formed by a part of the first plate portion 2204 in an overhanging manner. Therefore, even when the storage section 2201 and the lid section 2202 are closed, and the second sidewall portion 2209 of the lid section 2202 is fitted around the first sidewall portion 2205 of the storage section 2201, the overhanging portion 2204a prevents the storage section 2201 from getting into the lid section 2202, and thus the thickness of the storage case may be maintained as a whole.
The outer surface of the first sidewall portion 2205 is formed with a recessed locking portion 2205a and the inner side surface of the second sidewall portion 2209 is formed with a locking projection 2209a at the position corresponding to the locking portion 2205a when the storage section 2201 and the lid section 2202 are closed. Therefore, when the storage section 2201 and the lid section 2202 are closed, the locking projection 2209a engages the locking portion 2205a to prevent an accidental opening of the storage section 2201 and the lid section 2202.
The first sidewall portion 2205 is formed with an engaging recess 2311a, 2311b, and the inner surface of the second sidewall portion 2209 is provided with the same number of positioning ribs 2362a, 2362b as the engaging recesses. When the storage case is closed, the engaging recesses 2311a, 2311b engage with the positioning ribs 2362a, 2362b. Such engagement prevents the first sidewall portion 2205 and the second sidewall portion 2209 from moving in parallel with each other. When the storage case is closed, the positioning ribs 2362a, 2362b are inserted into the engaging recesses 2311a, 2311b for positioning between members. Therefore, engagement between the locking projections 2209a, 2209b and the locking portions 2205a, 2205b is ensured, and thus the lid section 2202 can be positioned at the appropriate position.
A plurality of cassette holding members 2313 are formed on the side of the storage section between the inner surface of the first plate portion 2204 and the inner surface of the first sidewall portion 2205. In the same manner, a plurality of cassette holding member 2314 are formed on the side of the lid section between the inner surface of the second plate portion 2208 and the inner surface of the second sidewall portion 2209.
Referring now to FIG. 59, the magnetic tape cassette 2381 is described. FIG. 59 is a perspective view of the magnetic tape cassette 2381 viewed from the bottom side, and thus the upper cassette half 2383 is shown below the lower cassette half 2385. There are formed circular openings 2387a, 2387b at two locations on the lower cassette half 2385, and reference rings 2389a, 2389b that is a dimension standard formed on the lower reel of the tape reels with the magnetic tape wound thereon.
On the front side of the magnetic tape cassette 2381, an outer lid 2391, an top lid 2397, and an inner lid (not shown) are provided for pivotal movement, and when it is mounted in the VTR or the like, the magnetic tape is pulled out after the outer lid 2391 is pivoted as shown by the arrow A in FIG. 59. There is formed a recessed front opening 2393 inside the outer lid 2391 at near the center in such a manner that the upper and lower cassette halves 2383, 2385 are notched, and there is provided a shoulder 2395, which is a recessed portion having generally the shape of a section at one end of the front opening 2393. The shoulder 2395 is formed at the rear of the cassette with respect to the top lid 2397.
In order to mount the magnetic tape cassette 2381 in the storage case 2350, the magnetic tape cassette 2381 is fitted within the sidewall portion 2205 as shown in FIG. 58 by a phantom line in such a manner that the front opening 93 is faced toward the opening locking rib 2207, and the reel locking ribs 2206a, 2206b are pushed to be inserted within the circular engaging holes B formed at the centers of the hubs of the tape reels, whereby the magnetic tape cassette 2381 is stored in the storage case 2350.
However, in the structure of the storage case 2350 described above, the following problem was recognized when the magnetic tape cassette 2381 is stored. As shown in FIG. 60, in the case where the magnetic tape cassette 2381 is inserted upside down, the top lid 2397 may be compressed by the opening locking portion 2207a of the opening locking rib 2207. When the top lid 2397 is compressed, the top lid 2397, and thus the outer lid 2391 and the inner lid (not shown) connected to the top lid may be deformed. When it is compressed with a force, these lids may be damaged. Since these lid serves to cover the magnetic tape for protection, deformation of these lids may give damage to the magnetic tape.
As shown in FIG. 61, even in a state in which the magnetic tape cassette 2381 is properly inserted, the tape reel 2410 may be displaced in case of drop in such a state. Then, the reel locking ribs 2206a, 2206b come into collision with the engaging hole B formed on the hub 2415 of the tape reel 2410, and thus the reel locking ribs 2206a, 2206b are subjected to an excessive load. When such an excessive load is applied repeatedly, there may be a case where the reel locking rib may be broken.
With such a circumstance in view, the fifth object of the present invention is to provide a storage case in which deformation that may be occurred when it is subjected to an impact in case of a drop can be prevented as well as, deformation of the lid can be prevented even when the magnetic tape cassette is inserted in a wrong way.
Recent years, a compact digital video camera of good portability came into wide use as a TV camera exclusively used for recording coverage. This type of camera is compact in size, but high-quality pictures can be obtained by processing digital signal. Therefore, it is widely used as equipment for business use among cameramen for broadcasting station or specialists for recording coverage.
The DVC to be used in the portable digital video camera come in three sizes being different in recording time period, and sold in the dedicated cassette storage case.
The magnetic tape cassette such as the DVC or the like described above are in many cases used for recording covered scenes, or brought to the broadcasting station as a material for editing/rerecording, and thus contains important pictures or scenes recorded therein. Therefore, it is preferable to store the recorded contents or the details to be consulted at the worksite together with the magnetic tape cassette. By organizing in this way, information on the recorded contents of the magnetic tape cassette or other related information, for example, on the site or the like can be checked out easily with the recorded contents later at the meeting.
Generally, this type of information in association with the recorded contents are shown by adhering a label on the magnetic tape cassette and the storage case, or by inserting a sheet of paper or information sheets such as a leaflet on which the recorded contents are listed in a space in the storage case. However, since the thickness of the space in the storage case is only as small as the thickness of the magnetic tape cassette, the amount of information sheets that can be stored with the magnetic tape cassette is small.
Accordingly, in Japanese Patent Application No. 230835/1998, the applicant of the present invention proposes a magnetic tape cassette storage case in which a storage section for storing the magnetic tape cassette, a lid section having a peripheral wall surrounding the storage section, and a connecting section for connecting the storage section and the lid section so as to be able to close and open are integrally formed of synthetic resin, and holding ribs are formed on the inner surface of the peripheral wall of the lid section on both sides for holding the magnetic tape cassette between itself and the bottom wall of the storage section by coming into contact with the peripheral edge on the surface of the magnetic tape cassette when the magnetic tape cassette is stored, and a sheet-holding rib is formed on at least one of holding ribs for holding one end of the information sheet between itself and the top plate, or the second plate portion of the lid section.
According to this magnetic tape cassette storage case, the information sheet can be stored in the storage case without jumping out, dropping off, or overhanging by clamping the end of the information sheet between the sheet-holding rib and the top plate when the information sheet is stored.
When such a magnetic tape cassette storage case is formed by injection molding, the holding rib with an undercut portion is molded by a slide core or a rocking core.
However, the direction of cutting or rocking of the core is the direction toward the center of the metal mold (inward of the metal mold), the core have to enter into the metal mold significantly toward the center thereof. In addition, when the overhanging amount of the undercut portion of the holding rib in association with the sheet-holding rib is significant, the line formed at the junction between the core and the metal mold extends to the center of the top plate of the lid of the magnetic tape cassette storage case. Therefore, for the storage case for transparent magnetic tape cassette, the appearance and the interior visibility may be spoiled.
Accordingly, the present invention is directed to solve the problem described above, and thus it is the sixth object to provide a less expensive metal mold for magnetic tape cassette storage cases and a magnetic tape cassette storage case with preferable appearance and interior visibility.
There are various types of magnetic tape cassettes, and the one used in the digital video camera described above is called DVC.
A magnetic tape cassette storage case used in the related art (storage case for DVCs) is shown in FIG. 62 by way of example. The storage case 2580 comprises a storage section 2581 for storing the magnetic tape cassette M, and a lid section 2591 connected to the storage section 2581 via a connecting section including the plate portion 2590 and the thin portion 2589. The storage section 2581 comprises a bottom plate 2582, or a first plate portion, having a plurality of mounting projections 2587, 2588 on the inner surface (upper surface in the figure) according to the recessed shape of the magnetic tape cassette M, and sidewalls 2583, 2583 and an end wall 2584, or a first sidewall portion, standing along the periphery of the bottom plate 2582 for fitting the magnetic tape cassette A. The upper end and the outer surface of the sidewall 2583 are formed with a positioning notch 2585 and a locking recess 2586 respectively for engaging the lid section 2591.
The lid section 2591 comprises a top plate 2592, or a second plate portion, and sidewalls 2593, 2593, and an end wall 2594, or the second sidewall portion, standing on the inner surface, or the surface opposing to the storage section 2581 of the top plate 2592 for fitting around the sidewall 2583 and the end wall 2584 of the storage section 2581. The inner surface of the sidewall 2593 is formed with a positioning rib 2595 and a locking claw 2596 for engaging the positioning notch 2585 and the locking recess 2586 of the storage section 2581 respectively. The inner surface of the sidewall 2593 is formed with a supporting rib 2597 having a bevel 2597a. The supporting rib 2597 supports the magnetic tape cassette M by the bevel 2597a when the magnetic tape cassette M is stored in the storage section 2581 and the lid section 2591 is closed.
The positioning rib 2595 and the supporting rib 2597 are in contact with the top plate 2592 at one end, and extend along the sidewall 2693. In contrast to it, the locking claw 2596 is provided near the distal end of the sidewall 2593 and is not in contact with the top plate 2592.
The storage case 2580 is molded by injection molding or the like. The metal mold comprises a main body of the metal mold, or the movable die for molding the inner side of the storage case 2580, and a fixed die for molding outside of the storage case 2580. The metal mold comprises a cavity for undercut portion on its side surface for molding a undercut portion such as a locking claw 2596 or the like, an ejector pin that inclines while ejecting the molded article out from the movable die by its tip surface (hereinafter referred to as “inclining pin”), and a slide core. While the inclining pin is inclining, the undercut portion is ejected from the cavity on the side surface of the inclining pin.
In the magnetic tape cassette storage case 2580 or the magnetic tape cassette storage case similar to the case 2580 of which the heights of the sidewall 2593 and the end wall 2594 of the lid section 2591 are in excess of a prescribed value, mold breathing tends to be worsened. This tendency is obvious especially for the storage case for the magnetic tape cassettes of which the heights of the sidewall 249 and the end wall 2594 of the lid section 2591 are not less than 6 mm, though it depends on the width of the gas bent or the position where the gas bent is disposed. Even when the heights of the sidewall 93 and the end wall 94 are less than 6 mm, imperfect mold breathing occurred.
When mold breathing is insufficient, bubbles are trapped in the sidewall 2593 of the storage case, which spoils the appearance of the transparent magnetic tape cassette storage case formed especially of polypropylene or the like.
With such a problem in view, it is the seventh object of the present invention to provide a metal mold for the storage cases for magnetic tape cassettes with good breathing, and a magnetic tape cassette storage case of good appearance that can be molded by the metal mold described above.